Skip to main content

Trace metal pollution in freshwater sediments of the world’s largest mercury mining district: sources, spatial distribution, and environmental implications



The Almadén mining district has suffered long-term extraction activity, and this has left significant areas of decommissioned mining liabilities. Nowadays, the uncontrolled runoff and related erosion and transport of trace metal-enriched soils and sediments affect the whole freshwater ecosystem. The goal of this study was to distinguish geogenic from mining-related sources of trace metals in freshwater sediments, to understand their dispersion in the watershed, and, finally, to evaluate the potential environmental implications for future corrective plans.

Materials and methods

Freshwater surface sediment samples were collected from ten points along the main streams of the watershed (nine inside the mining district and one control point outside the district). Sediments were air dried and analyzed by different standard methods for pH, total major and trace element concentrations, total organic carbon, and grain size. In addition to the determination of the enrichment factor, a multi-statistical approach was applied involving discriminant analysis, Student’s t test, and Mann-Whitney U analysis.

Results and discussion

Sediments inside the district contained high levels of major and trace elements with respect to the control point. The predominance of fine fractions in these sediment samples appears to be one of the most important factors that affects trace metal concentrations. Among the trace elements, not only Hg but also As, Pb, and Zn are discriminative geochemical markers, thus allowing the identification of the different mining sources and their individual or combined impact throughout the district. Furthermore, the high enrichment factors obtained for As, Hg, Pb, and Zn with respect to the local background values highlight the persistent and severe impact from the decommissioned mines on the freshwater surficial sediments and their potential geoavailable risk for aquatic organisms.


The geochemistry of freshwater sediments alone demonstrates that different contamination sources are recognizable within the mining district and these can be related to the specific decommissioned mines. In addition, the discrete sources can be clearly distinguished on the basis of the statistical analysis of the geochemical data. Despite the closure of the mines, stream sediments are still the main repository of trace metals within the district, and they are therefore a potential threat to the freshwater ecosystem.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6


  • Adriano DC (2001) Trace elements in terrestrial environments; biogeochemistry, bioavailability and risks of metals, 2nd edn. Springer, New York, p. 866

    Book  Google Scholar 

  • Audry S, Blanc G, Schäfer J (2005) The impact of sulphide oxidation on dissolved metal (Cd, Zn, Cu, Cr, Co, Ni, U) inputs into the Lot–Garonne fluvial system (France). Appl Geochem 20:919–931

    CAS  Article  Google Scholar 

  • Berzas Nevado JJ, Bermejo LG, Martı́n-Doimeadios, RR (2003) Distribution of mercury in the aquatic environment at Almaden, Spain. Environ Pollut 122:261–271

  • Berzas Nevado JJ, Martín-Doimeadios RCR, Moreno MJ (2009) Mercury speciation in the Valdeazogues River–La Serena reservoir system: influence of Almadén (Spain) historic mining activities. Sci Total Environ 407(7):2372–2382

    CAS  Article  Google Scholar 

  • Bi X, Feng X, Yang Y, Qiu G, Li G, Li F, et al. (2006) Environmental contamination of heavy metals from zinc smelting areas in Hezhang County, western Guizhou, China. Environ Int 32:883–890

    CAS  Article  Google Scholar 

  • Buchman, MF (2008) NOAA Sreening Quick Reference Tables, NOAA OR&R Report 08–1, Seattle WA, Office of Response and Restoration Division, National Oceanic and Atmospheric Administration, 34 pp

  • Chen CW, Kao CM, Chen CF, Dong CD (2007) Distribution and accumulation of heavy metals in the sediments of Kaohsiung Harbor, Taiwan. Chemosphere 66(8):1431–1440

    CAS  Article  Google Scholar 

  • Costley CT, Mossop KF, Dean JR, Garden LM, Marshall J, Carroll J (2000) Determination of mercury in environmental and biological samples using pyrolysis atomic absorption spectrometry with gold amalgamation. Anal Chim Acta 405:179–183

    CAS  Article  Google Scholar 

  • Covelli S, Langone L, Acquavita A, Piani R, Emili A (2012) Historical flux of mercury associated with mining and industrial sources in the Marano and Grado lagoon (northern Adriatic Sea). Estuar Coast Shelf Sci 13:7–19

    Article  Google Scholar 

  • Dago À, González I, Ariño C, Martínez-Coronado A, Higueras P, Diaz-Cruz JM, Esteban M (2014) Evaluation of mercury stress in plants from the Almadén mining district by analysis of phytochelatins and their Hg complexes. Environ Sci Technol 48:6256–6263

    CAS  Article  Google Scholar 

  • De Vleeschouwer F, Gérard L, Goormaghtigh C, Mattielli N, Le Roux G, Fagel N (2007) Atmospheric lead and heavy metal pollution records from a Belgian peat bog spanning the last two millenia: human impact on a regional to global scale. Sci Total Environ 377:282–295

    Article  Google Scholar 

  • Delgado J, Barba-Brioso C, Nieto JM, Boski T (2011) Speciation and ecological risk of toxic elements in estuarine sediments affected by multiple anthropogenic contributions (Guadiana saltmarshes, SW Iberian peninsula): I. Surficial sediments. Sci Total Environ 409:3666–3679

    CAS  Article  Google Scholar 

  • Díaz Puente, FJ (2013) Variación de la actividad fisiológica de la microflora del suelo en terrenos afectados por actividades mineras. PhD Thesis Universidad Complutense de Madrid (in Spanish)

  • Eckel W, Rabinowitz M, Foster G (2002) Investigation of unrecognized former secondary lead smelting sites: confirmation by historical sources and elemental ratios in soil. Environ Pollut 117:273–279

    CAS  Article  Google Scholar 

  • Folk RL (1951) Stages of textural maturity in sedimentary rocks. J Sediment Res 21:127–130

    Article  Google Scholar 

  • Förstner U (2003) Geochemical techniques on contaminated sediments—river basin view. Environ Sci Pollut Res Int 10:58–68

    Article  Google Scholar 

  • Foulds SA, Brewer PA, Macklin MG, Haresign W, Betson RE, Rassner SME (2014) Flood-related contamination in catchments affected by historical metal mining: an unexpected and emerging hazard of climate change. Sci Total Environ 476:165–180

    Article  Google Scholar 

  • García R, Petit-Domínguez MD, Rucandio MI, González JA (2011) Provenance of loess from the Spanish central region: chemometric interpretation. Geol Mag 148:481–491

    Article  Google Scholar 

  • Garcia-Ordiales, E (2016a) Incidencia de la minería abandonada en la cuenca del Rio Valdeazogues y valoración del impacto en el sistema acuático. Escuela de Ingenieria de Minas, Energia y Materiales, Grupo Hunosa, Universidad de Oviedo Ed., ISBN 978–84–608-6349-6 (in Spanish)

  • García-Ordiales E, Loredo J, Esbrí JM, Lominchar MA, Millán R, Higueras P (2014) Stream bottom sediments as a mean to assess metal contamination in the historic mining district of Almadén (Spain). Int J Min Reclam Environ 28(6):377–388

  • García-Ordiales E, Esbrí JM, Covelli S, López-Berdonces MA, Higueras PL, Loredo J (2016b) Heavy metal contamination in sediments of an artificial reservoir impacted by long-term mining activity in the Almadén mercury district (Spain). Environ Sci Pollut Res Int 23:6024–6038

    Article  Google Scholar 

  • Gosar M, Pirc S, Bidovec M (1997) Mercury in the Idrijca River sediments as a retection of mining and smelting activities of the Idrija mercury mine. J Geochem Explor 58:125–131

    CAS  Article  Google Scholar 

  • Gray JE, Hines ME, Higueras PL, Adatto I, Lasorsa BK (2004) Mercury speciation and microbial transformations in mine wastes, stream sediments, and surface waters at the Almadén Mining District, Spain. Environ Sci Technol 38:4285–4292

    CAS  Article  Google Scholar 

  • Hammarstrom JM, Seal RR II, Meier AL, Kornfeld JM (2005) Secondary sulfate minerals associated with acid drainage in the eastern US: recycling of metals and acidity in surficial environments. Chem Geol 215:407–431

    CAS  Article  Google Scholar 

  • Hashmi MZ, Yu C, Shen H, Duan D, Shen C, Lou L, Chen Y (2013) Risk assessment of heavy metals pollution in agricultural soils of Siling reservoir watershed in Zhejiang Province, China. BioMed Res Int. doi:10.1155/2013/590306

    Google Scholar 

  • Hernández A, Jébrak M, Higueras P, Oyarzun R, Morata D, Munhá J (1999) The Almadén mercury mining district. Spain Miner Deposita 34:539–548

    Article  Google Scholar 

  • Higueras P, Amorós JA, Esbrí JM, García-Navarro FJ, Pérez de los Reyes C, Moreno G (2012) Time and space variations in mercury and other trace element contents in olive tree leaves from the Almadén Hg-mining district. J Geochem Explor 123:143–151

    CAS  Article  Google Scholar 

  • Higueras P, Oyarzun R, Iraizoz JM, Lorenzo S, Esbrí JM, Martínez Coronado A (2011) Low-cost geochemical surveys for environmental studies in developing countries: testing a field portable FRX instrument under quasi-realistic conditions. J Geochem Explor 113:3–12

    Article  Google Scholar 

  • Higueras P, Oyarzun R, Lillo J, Morata D (2013) Intraplate mafic magmatism, degasification, and deposition of mercury: the giant Almadén mercury deposit (Spain) revisited. Ore Geol Rev 51:93–102

    Article  Google Scholar 

  • Higueras P, Oyarzun R, Lillo J, Sánchez Hernández JC, Molina JA, Esbrí JM, Lorenzo S (2006) The Almadén district (Spain): anatomy of one of the world’s largest Hg-contaminated sites. Sci Total Environ 356:112–124

    CAS  Article  Google Scholar 

  • Higueras P, Oyarzun R, Lunar R, Sierra J, Parras J (1999) The Las Cuevas mercury deposit, Almadén district (Spain): unusual case of deep-seated advanced argillic alteration related to mercury mineralization. Mineral Deposita 34:211–214

    CAS  Article  Google Scholar 

  • Higueras P, Oyarzun R, Munhá J, Morata D (2000a) Palaeozoic magmatic-related hydrothermal activity in the Almadén syncline, Spain: a long-lasting Silurian to Devonian process? Appl Earth Sci 109:199–202

    Article  Google Scholar 

  • Higueras P, Oyarzun R, Munhá J, Morata D (2000b) The Almadén mercury metallogenic cluster (ciudad real, Spain): alkaline magmatism leading to mineralization processes at an intraplate tectonic setting. Rev Soc Geol Esp 13:105–119

    Google Scholar 

  • Higueras P, Oyarzun R, Morata D (2013) Intraplate mafic magmatism, degasification, and deposition of mercury: the giant Almadén Hg deposit (Spain) revisited. Ore Geol Rev 51:93–102

    Article  Google Scholar 

  • Higueras P, Oyarzun R, Iraizoz JM, Lorenzo S, Esbrí JM, Martinez-Coronado A (2012) Low-cost geochemical surveys for environmental studies in developing countries: testing a field portable XRF instrument under quasi-realistic conditions. J Geochem Explor 113:3–12

    CAS  Article  Google Scholar 

  • Hildebrand SG, Huckabee JW, Sanz Diaz F, Cansen SA, Solomon JA, Kumar KD (1980) Distribution of mercury in the environment at Almaden, Spain. Report ORNL/TM-7446 Oak Ridge Nacional Laboratory Oak Ridge, Tennesse, pp 193–198

  • ISO (1994) Soil quality, Determination of pH. AENOR

  • Lecce SA, Pavlowsky RT (2014) Floodplain storage of sediment contaminated bymercury and copper from historic gold mining at Gold Hill, North Carolina, USA. Geomorphology 206:122–132

    Article  Google Scholar 

  • Li Q, Ji H, Qin F, Tang L, Guo X, Feng J (2014) Sources and the distribution of heavy metals in the particle size of soil polluted by gold mining upstream of Miyun reservoir, Beijing: implications for assessing the potential risks. Environ Monit Assess 186:6605–6626

    CAS  Article  Google Scholar 

  • Loredo J, Pettit-Dominguez MD, Ordoñez A, Galan MP, Fernandez-Martinez R, Alvarez R, Rucandio MI (2010) Surface water monitoring in the mercury mining district of Asturias (Spain). J Hazard Mater 176:323–332

    CAS  Article  Google Scholar 

  • Millán R, Gamarra R, Schmid T, Sierra MJ, Quejido AJ, Sánchez DM, Vera R (2006) Mercury content in vegetation and soils of the Almadén mining area (Spain). Sci Total Environ 368:79–87

    Article  Google Scholar 

  • Millán R, Lominchar MA, Rodríguez-Alonso J, Schmid T, Sierra MJ (2014) Riparian vegetation role in mercury uptake (Valdeazogues River, Almadén, Spain). J Geochem Explor 140:104–110

    Article  Google Scholar 

  • Moncur MC, Ptacek CJ, Blowes DW, Jambor JL (2005) Release, transport and attenuation of metals from an old tailings impoundment. Appl Geochem 20:639–659

    CAS  Article  Google Scholar 

  • Müller G (1979) Schwermetalle in den Sedimenten des Rheins-Veränderungen seit. Umschau 79:778–783

    Google Scholar 

  • Palero F, Lorenzo S (2009) Mercury mineralization in the region of Almadén. In: García-Cortés A, Agueda-Villar J, Palacio Suárez-Valgrande J, Salvador González CI (eds) Spanish geological frameworks and geosites: an approach to spanish geological heritage of international relevance. Ins Geol Min Esp, Madrid, pp 65–72

  • Palero, FJ (1991) Evolución Geotectónica y Yacimientos Minerales de la Región del Valle de Alcudia (Sector Meridional de la Zona Centroibérica), Ph.D. diss., Universidad de Salamanca (in Spanish)

  • Petit-Dominguez MD, Rucandio MI, Galan-Saulnier A, Garcia-Gimenez R (2008) Usefulness of geological, mineralogical, chemical and chemometric analytical techniques in exploitation and profitability studies of iron mines and their associated elements. J Geochem Explor 98:116–128

    CAS  Article  Google Scholar 

  • Potter BB, Wimsatt JC (2012) USEPA method 415.3: Quantifying TOC, DOC, and SUVA. Journal: American Water Works Association, 104(6)

  • Puche O (1989) Mecanismos estructurales de los volcanismos paleozoicos en la región Alcudiense. PhD Thesis Universidad Politecnica de Madrid (in Spanish)

  • Resongles E, Casiot C, Freydier R, Dezileau L, Viers J, Elbaz-Poulichet F (2014) Persisting impact of historical mining activity to metal (Pb, Zn, Cd, Tl, Hg) and metalloid (as, Sb) enrichment in sediments of the Gardon River, southern France. Sci Total Environ 481:509–521

    CAS  Article  Google Scholar 

  • Rytuba JJ, Rye RO, Hernandez AM, Dean JA, Arribas A (1988) Genesis of Almadén type mercury deposits, Almadén, Spain. Int Geol Congr Washington, 2–741

  • Saínz de Baranda B (1988) Estudio de las mineralizaciones de Zn-Pb-Cu asociadas a los materiales volcánicos alcalinos devónicos en el sinclinal de Almaden. Ciudad Real. PhD Thesis Universidad Complutense de Madrid (in Spanish)

  • Sáinz de Baranda B, Lunar Hernández R (1989) El volcanismo alcalino pre-hercinico del sinclinal de Almadén. Estud Geol 45:337–348

    Article  Google Scholar 

  • Salomons W (1995) Environmental impact of metals derived from mining activities: processes, predictions. Prev J Geochem Explor 52:5–23

    CAS  Article  Google Scholar 

  • Siepak J (1999) Total organic carbon (TOC) as sum parameter of water pollution in selected polish rivers (Vistula, Odra and Warta). Acta Hydrochim Hydrobiol 27:282

    CAS  Article  Google Scholar 

  • Skordas K, Kelepertzis E, Kosmidis D, Panagiotaki P, Vafidis D (2014) Assessment of nutrients and heavy metals in the surface sediments of the artificially lake water reservoir Karla, Thessaly, Greece. Environ Earth Sci 73:4483–4493

    Article  Google Scholar 

  • Spellman FR, Whiting NE (2013) Handbook of Mathematics and Statistics for the Environment. CRC Press, 838 pp

  • Sumner ME (1994) Measurement of soil pH: problems and solutions. Commun Soil Sci Plant Anal 25:859–879

    CAS  Article  Google Scholar 

  • Telford K, Maher W, Krikowa F, Foster S, Ellwood MJ, Ashley PM, Lockwood PV, Wilson SC (2009) Bioaccumulation of antimony and arsenic in a highly contaminated stream adjacent to the Hillgrove mine, NSW, Australia. Environ Chem 6:133–143

    CAS  Article  Google Scholar 

  • Tipping E, Marker A, Butterwick G, Collett G, Crawell P, Ingram J, Leach D, Lishman J, Pinder A, Simon B (1997) Organic carbon in the Humber rivers. Sci Total Environ 195:345–355

    Article  Google Scholar 

  • U.S. EPA (1997) Mercury study report to Congress, Vols. I-VIII; U.S. Environmental Protection Agency: Washington, DC; EPA-452/R-97-003

  • Wilson NJ, Craw D, Hunter K (2004) Antimony distribution and environmental mobility at an historic antimony smelter site, New Zealand. Environ Pollut 129:257–266

    CAS  Article  Google Scholar 

  • Zhao Q, Liu S, Deng L, Dong S, Wang C (2013) Longitudinal distribution of heavymetals in sediments of a canyon reservoir in Southwest China due to dam construction. Environ Monit Assess 185:6101–6110

Download references


The authors are warmly grateful to Dr. Neil Thompson for English proof reading.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Efrén Garcia-Ordiales.

Ethics declarations


This study is part of a PhD thesis (2014) entitled “Incidences of mining in the Valdeazogues River basin and impact assessment in the aquatic system” by Efrén Garcia-Ordiales and supported by the Spanish Ministry of Science and Innovation (grant numbers BES-2010-040450, CGL2009-13171-C03-03 and EEBB-I-13-07336) and by the Asturias Regional Ministry of Education and Science (grant number ECOEMP-2013).

Additional information

Responsible editor: Jadran Faganeli

Electronic supplementary material


(DOCX 90 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Garcia-Ordiales, E., Loredo, J., Covelli, S. et al. Trace metal pollution in freshwater sediments of the world’s largest mercury mining district: sources, spatial distribution, and environmental implications. J Soils Sediments 17, 1893–1904 (2017).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Contamination assessment
  • Freshwater sediments
  • Metals
  • Mercury
  • Mining activity